Prevent a Client from Connecting to SSID

I have a question that may seem odd...
I would like to prevent the clients to connect to a specific SSID.
For example:
The SSID "Sisko" is broadcasted and can be found by the client. - Requirement.
The SSID "Sisko" is unprotected and open to connect to, a typical Guest Access solution.
I do not want the clients to be able to connect to this specific SSID.
I do want the clients to be able to connect to other SSID:s.

Is there a way of doing this? A Registry hack or something?
I have full control of the clients.

yes there is a way to do that.
if u can specify the clients u want by giving ur router, the mac address of
the clients pc or laptop as the case may be on the security settings page.
so any client who does not have that mac address will not be able to access
the net work.

Thanks for your suggestion. But we do got a problem to manage
this solution. There are about 80 000 clients that should be
stopped. Seems a little hard to set up the MAC adress list in
this enviroment. :o) And I do wonder what heppends with the
performance with such big list.

The problem is to deny access to a specific SSID, for choosen clients. The number of clients are quite big. Approx 80 000 clients. About 10 000 of the clients are ment to connect to a specific WLAN. Those clients are no problem.
The problem is to prevent the clients that should not connect.
The clients are controlled by AD in a W2k3 server.
I have thought of missconfigure a WLAN config, puch it out to the clients with a GPO, but it seems to create problems for the client. So I can not do that either...

Sorry to say, but this solution will not work.
The problem is to deny a couple of clients, that uses
uncontrolled (homeWLAN etc) to connect to the guestWLAN. We are
going to use the VLAN functionality. One for approved WLAN for
domain connection, and one for guests. The clients that are not
approved to use the domain wireless should be denied access to
the Guest WLAN.
The guest WLAN is a uncrypted open WLAN.

Hi. I hope you are well. To answer your question or give a slight solution
to your problem and the easiest way i think is to manually configure an
access list with in the router by allowing only the MAC address of each of
the 10 000 clients to have access to the WLAN. This is easily done by an
implementation of a WEP 128 bit security key or network key. This network
key is applied to each of the 10 000 clients that you want to have access
while the other 70 000 clients wouldn't.

Hi, and thanks for your answer.
..and yes I am well and I hope you are as well.

I can not create an access list to the clients that are allowed to access this SSID because the MAC adresses are unknown.
The broadcasted SSID is a Guest Access WLAN. Similar to a HotSpot. I want to prevent our domain users to connect to this WLAN.

The 10 000 clients that are granted access to the domain via WLAN are set to a specific preffered SSID, set by a GPO by the AD. The rest, approximatly 80 000 clients are supposed to be able to connect to a wireless LAN but NOT to the Guest access SSID.

By the way, the solution could be based on: not allow any of the domain clients to connect to this specific SSID.

And I think a MAC adress list is to big to handle, and there are no possidility to control the MAC Adress if the user byes a WLAN NIC for use at home...